Semiconductor Constructions, Memory Arrays, Methods of Forming Semiconductor Constructions and Methods of Forming Memory Arrays

ABSTRACT

Some embodiments include methods of forming semiconductor constructions. Carbon-containing material is formed over oxygen-sensitive material. The carbon-containing material and oxygen-sensitive material together form a structure having a sidewall that extends along both the carbon-containing material and the oxygen-sensitive material. First protective material is formed along the sidewall. The first protective material extends across an interface of the carbon-containing material and the oxygen-sensitive material, and does not extend to a top region of the carbon-containing material. Second protective material is formed across the top of the carbon-containing material, with the second protective material having a common composition to the first protective material. The second protective material is etched to expose an upper surface of the carbon-containing material. Some embodiments include semiconductor constructions, memory arrays and methods of forming memory arrays.

TECHNICAL FIELD

Semiconductor constructions, memory arrays, methods of formingsemiconductor constructions and methods of forming memory arrays.

BACKGROUND

Memory is one type of integrated circuitry, and is used in electronicsystems for storing data. Integrated memory is usually fabricated in oneor more arrays of individual memory cells. The memory cells areconfigured to retain or store memory in at least two differentselectable states. In a binary system, the states are considered aseither a “0” or a “1”. In other systems, at least some individual memorycells may be configured to store more than two levels or states ofinformation.

One type of memory is phase change memory (PCM). Such memory utilizesphase change material as a programmable material. Example phase changematerials that may be utilized in PCM are chalcogenide materials.

The phase change material reversibly transforms from one phase toanother through application of appropriate stimulus. Each phase may beutilized as a memory state, and thus an individual PCM cell may have twoselectable memory states that correspond to two inducible phases of thephase change material.

The phase change materials may be detrimentally affected (i.e.,“poisoned”) if they are exposed oxygen, and accordingly it is desired todevelop new architectures and fabrication methods which alleviate orprevent such oxygen exposure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-3 are cross-sectional side views of a construction showingvarious process stages of an example method of forming an opening for anelectrical interconnect. FIG. 1 shows a preliminary processing stage;and FIGS. 2 and 3 show process stages that can follow that of FIG. 1.FIG. 2 shows a process stage that can occur in the absence of maskmisalignment, and FIG. 3 show a process stage that can occur if there issome mask misalignment.

FIGS. 4-6 are a top view and cross-sectional side views of aconstruction at a processing stage of an example embodiment method. Thecross-sectional views of FIGS. 5 and 6 are along the lines A-A and B-B,respectively, of FIG. 4.

FIGS. 7-9 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.4-6. The cross-sectional views of FIGS. 8 and 9 are along the lines A-Aand B-B, respectively, of FIG. 7.

FIGS. 10-12 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.7-9. The cross-sectional views of FIGS. 11 and 12 are along the linesA-A and B-B, respectively, of FIG. 10.

FIGS. 13-15 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.10-12. The cross-sectional views of FIGS. 14 and 15 are along the linesA-A and B-B, respectively, of FIG. 13.

FIGS. 16-18 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.13-15. The cross-sectional views of FIGS. 17 and 18 are along the linesA-A and B-B, respectively, of FIG. 16.

FIGS. 19-21 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.16-18. The cross-sectional views of FIGS. 20 and 21 are along the linesA-A and B-B, respectively, of FIG. 19.

FIGS. 22-24 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.19-21. The cross-sectional views of FIGS. 23 and 24 are along the linesA-A and B-B, respectively, of FIG. 22.

FIGS. 25-27 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.22-24. The cross-sectional views of FIGS. 26 and 27 are along the linesA-A and B-B, respectively, of FIG. 25.

FIGS. 28-30 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.25-27. The cross-sectional views of FIGS. 29 and 30 are along the linesA-A and B-B, respectively, of FIG. 28.

FIGS. 31-33 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.28-30. The cross-sectional views of FIGS. 32 and 33 are along the linesA-A and B-B, respectively, of FIG. 31.

FIGS. 34-36 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.31-33. The cross-sectional views of FIGS. 35 and 36 are along the linesA-A and B-B, respectively, of FIG. 34.

FIGS. 37-39 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.34-36. The cross-sectional views of FIGS. 38 and 39 are along the linesA-A and B-B, respectively, of FIG. 37.

FIGS. 40-42 are a top view and cross-sectional side views of aconstruction at an example processing stage subsequent to that of FIGS.37-39. The cross-sectional views of FIGS. 41 and 42 are along the linesA-A and B-B, respectively, of FIG. 40.

FIG. 43 is a view of a construction at a processing stage analogous tothat of FIG. 42 in accordance with an embodiment alternative to that ofFIG. 42.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

A problem that may occur during fabrication of integrated circuitrycomprising oxygen-sensitive material is described with reference toFIGS. 1-3.

FIG. 1 shows a construction 200 comprising oxygen-sensitive material 202beneath an electrically conductive cap 204. In some embodiments, thematerials 202 and 204 may be part of a PCM cell; with theoxygen-sensitive material being phase change material (such aschalcogenide) and the cap being an electrode. The materials 202 and 204are part of a structure 207 having sidewalls 205 that extend along boththe oxygen-sensitive material 202 and the cap 204. A first electricallyinsulative material 206 is over the cap and along sidewalls of thestructure 207. The first electrically insulative material may comprise anon-oxygen-containing composition, such as, for example, siliconnitride; and may be utilized as a protective material to protectoxygen-sensitive material 202 from being exposed to oxygen. A secondelectrically insulative material 208 is laterally outward of the firstelectrically insulative material, and is spaced from theoxygen-sensitive material 202 by the protective material 206. Theelectrically insulative material 208 may comprise oxygen; and in someembodiments may comprise, for example, one or more of silicon dioxide,borophosphosilicate glass (BPSG), phosphosilicate glass (PSG), aluminumoxide, etc. The electrically insulative materials 206 and 208 may bealternatively referred to as dielectric materials; with the terms“electrically insulative material” and “dielectric material” beingsynonymous with one another.

FIG. 2 shows a processing stage subsequent to that of FIG. 1, and showsan opening 210 formed through material 206 to expose an upper surface ofcap 204. In the embodiment of FIG. 2, the opening is properly alignedwith the cap 204 and accordingly only the cap is exposed within theopening. In contrast, FIG. 3 shows a processing stage analogous to thatof FIG. 2, except that opening 210 is misaligned relative to cap 204.Thus, the opening extends along one of the sidewalls 205 to expose aregion of the oxygen-sensitive material 202. The exposed region ofoxygen-sensitive material 202 may problematically become poisoned byoxygen in a subsequent processing stage.

Some embodiments described herein include methods of alleviating orpreventing the problem described with reference to FIGS. 1-3. Someembodiments include new architectures.

FIGS. 4-6 diagrammatically illustrate a portion of a semiconductorconstruction 10 at a preliminary processing stage of an exampleembodiment method. FIG. 4 shows a top view of the construction, andFIGS. 5 and 6 show cross-sections along the lines A-A and B-B,respectively, of FIG. 4.

The construction 10 comprises a p-type doped region 12, and variousdoped regions 14, 16, 18 and 20 over the region 12. The regions 12, 14,16 and 18 are patterned into a plurality of pedestals 21 (only some ofwhich are labeled), with such pedestals being separated from one anotherby intervening dielectric material 22. Such material 22 may comprise anysuitable composition or combination of compositions, and in someembodiments may comprise oxygen-containing material; such as, forexample, silicon dioxide, borophosphosilicate glass (BPSG),phosphosilicate glass (PSG), etc. The doped regions 14, 16, 18 and 20correspond to doped semiconductor material, such as doped silicon.

The regions 16 and 20 are heavily-doped, and thus are indicated to be n+doped and p+ doped, respectively. The p-type doped region 12, n-typedoped region 16 and p-type doped region 20 together form pn diodes insome embodiments. The regions 14 and 18 are lightly doped, and areutilized as graded junctions to improve performance of such diodes. Insome embodiments, the regions 12, 16 and 20 may be regions of bipolarjunction transistors.

Electrically conductive material 24 is formed across the tops of thediodes. Such electrically conductive material may comprise any suitablecomposition or combination of compositions; and in some embodiments maycomprise metal silicide (such as, for example, cobalt silicide, titaniumsilicide, nickel silicide, etc.). The conductive material 24 may beformed by silicidation of upper surfaces of doped regions 20 in someembodiments. Although the conductive material 24 is shown to have anupper surface substantially coplanar with the upper surface ofinsulative material 22, in other embodiments the conductive material 24may have an upper surface which is above or below the upper surface ofinsulative material 22.

In the shown embodiment, the tops of pedestals 21 are square (asindicated by the square shape of material 24 in the top view of FIG. 4),but in other embodiments the tops of the pedestals may have othershapes; such as, for example, polygonal shapes, round shapes, ellipticalshapes, etc.

The pedestals 21 are arranged in a grid (as indicated by the material 24being arranged in a grid in the top view of FIG. 4). Such grid has afirst direction along an axis 5, and a second direction along an axis 7.In the shown embodiment, the second direction is substantiallyorthogonal to the first direction; with the term “substantiallyorthogonal” meaning that the directions orthogonal to within reasonabletolerances of fabrication and measurement. The cross-section of FIG. 5is along axis 7, and that of FIG. 6 is along axis 5.

The cross-sections of FIGS. 5 and 6 show that the pedestals 21 extenddeeper along the cross-section of FIG. 5 than along the cross-section ofFIG. 6. Specifically, the pedestals extend through regions 14 and 16,and into region 12 along the cross-section of FIG. 5; and extend onlypartially into region 16 along the cross-section of FIG. 6. In someembodiments, heavily-doped region 16 may be considered to form wordlineswhich interconnect pluralities of diodes along the direction of axis 5;with an example wordline 28 being illustrated in FIG. 6.

The illustrated pn diodes are examples of access devices which may beincorporated into a memory array. Other access devices may be utilizedin place of, or in addition to, the illustrated diodes in otherembodiments. Such other access devices may include, for example, fieldeffect transistors, bipolar junction transistors, PIN diodes, etc.

In some embodiments, construction 10 may be considered to comprise asemiconductor substrate. The term “semiconductor substrate” means anyconstruction comprising semiconductive material, including, but notlimited to, bulk semiconductive materials such as a semiconductive wafer(either alone or in assemblies comprising other materials), andsemiconductive material layers (either alone or in assemblies comprisingother materials). The term “substrate” refers to any supportingstructure, including, but not limited to, the semiconductor substratedescribed above. Construction 10 may correspond to a semiconductorsubstrate containing one or more materials associated with integratedcircuit fabrication in some embodiments. Some of the materials may beunder the shown region 12 and/or may be laterally adjacent the shownregion 12; and may correspond to, for example, one or more of refractorymetal materials, barrier materials, diffusion materials, insulatormaterials, etc. In some embodiments, the regions 12, 14, 16, 18 and 20may comprise monocrystalline silicon.

Referring to FIGS. 7-9, electrically insulative material 26 is formedacross construction 10, and subsequently openings are formed throughmaterial 26 to conductive material 24 and filled with a conductivematerial 30.

The conductive material 30 may comprise any suitable composition orcombination of compositions; and in some embodiments may comprise,consist essentially of, or consist of one or more of various metals (forexample, tungsten, titanium, etc.), metal-containing compositions (forinstance, metal nitride, metal carbide, metal silicide, etc.), andconductively-doped semiconductor materials (for instance,conductively-doped silicon, conductively-doped germanium, etc.). In anexample embodiment, material 30 may comprise a liner of titanium nitridearound a fill of tungsten.

The insulative material 26 may comprise any suitable composition orcombination of compositions. In some embodiments, material 26 maycomprise a same composition as material 22, and accordingly material 26may comprise an oxygen-containing composition, such as, for example, oneor more of silicon dioxide, BPSG, PSG, etc. In some embodiments material26 may comprise a different composition than material 22.

A planarized surface 31 is shown extending across materials 30 and 26.Such surface may result from chemical-mechanical polishing (CMP). Forinstance, material 30 may be initially provided to overfill the openingswithin material 26, and subsequently CMP may be utilized to removeexcess material 30 and form the shown planarized surface 31.

The material 30 may be considered to form a plurality conductive plugs,with upper regions of the conductive plugs corresponding to a pluralityof spaced-apart electrical nodes 32 (only some of which are labeled)across the top of construction 10.

The electrical nodes are arranged in the grid comprising the firstdirection along axis 5 and the second direction along axis 7.

Referring to FIGS. 10-12, spaced-apart patterning structures 34-36 areformed over planarized surface 31. In the shown embodiment, thepatterning structures are lines extending along the direction of axis 5.Each patterning structure comprises a top (for instance, the top 37 ofstructure 35) and a pair of opposing sidewalls (for instance, thesidewalls 39 and 41 of structure 35). In some embodiments, one of thesidewalls of a patterning structure may be referred to as a firstsidewall and the other may be referred to as a second sidewall.Accordingly, in some embodiments sidewalls 39 and 41 may be referred toas a first sidewall and a second sidewall, respectively. The firstsidewall 39 passes across and directly over one set of nodes, and thesecond sidewall 41 passes across and directly over a different set ofnodes. In some embodiments, the nodes under the first sidewall may bereferred to as a first set of nodes, and the nodes under the secondsidewall may be referred to as a second set of nodes.

The patterning structures span spaces between the nodes 32 and partiallyoverlap the nodes. Portions of the nodes are shown in dashed-line in thetop view of FIG. 10 to indicate that such portions are under thepatterning structures 34-36.

The patterning structures comprise a material 38. Such material maycomprise any suitable composition, or combination of compositions; andin some embodiments may comprise, consist essentially of, or consist ofsilicon nitride.

The patterning structures 34-36 may comprise any suitable dimensions. Insome embodiments, nodes 32 may be formed on a pitch P, and thepatterning structures may be spaced from one another by a distance Dcomparable to such pitch. For instance, in some embodiments the pitchmay be a dimension within a range of from about 40 nanometers to about60 nanometers, and D may be substantially the same dimension. Thepatterning structures have a thickness T. In some embodiments, suchthickness may be within a range of from about equal to the pitch toabout three-times the pitch; and in some example embodiments may bewithin a range of from about 60 nanometers to about 100 nanometers.

The patterning structures may be formed with any suitable processing;including, for example, forming a layer of material 38 across planarizedsurface 31 followed by utilization of a patterned mask (not shown) andone or more etches to form the illustrated lines of material 38. Thepatterned mask may comprise any suitable mask, including, for example, aphotolithographically-patterned photoresist mask and/or a mask formedutilizing pitch-modification methodologies.

Referring to FIGS. 13-15, heater material 40 is formed along sidewallsof the patterning structures 34-36, and dielectric materials 42 and 44are formed across the heater material 40. The heater material 40 isshown to be patterned to be angled plates that extend along the sidewallsurfaces of the patterning structures (for instance, surfaces 37 and 39of structure 35), and that extend across upper regions of nodes 32. Theheater material may be patterned into such configuration with anysuitable methodology. For instance, in some embodiments the heatermaterial may be formed to extend conformally across the patterningstructures 34-36 and the spaces between the patterning structures, andthen the heater material may be patterned utilizing a mask (not shown)and one or more etches to form the heater material into theconfiguration shown in FIGS. 14 and 15. The dielectric material 42 isshown formed across the heater material. In some embodiments, theentirety of dielectric material 42 may be formed after patterning theheater material into the shown configuration of FIGS. 14 and 15. Inother embodiments, some of the dielectric material may be formed priorto patterning the heater material, and patterned with the heatermaterial; and then a remainder of dielectric material 42 may be formed.

The heater material 40 may have any suitable thickness, and in someembodiments may have a thickness within a range of from about 5nanometers to about 10 nanometers. The heater material may comprise anysuitable composition or combination of compositions. In someembodiments, the heater material may comprise titanium and nitrogen; andmay be, for example, TiN, a TiN composite, doped TiN, etc. In someembodiments, the heater material may comprise TiSiN (where the formulaindicates the components within the listed compound, rather thandesignating a specific stoichiometry of such components). The heatermaterial may be formed with any suitable processing, including, forexample, one or more of atomic layer deposition (ALD), chemical vapordeposition (CVD) and physical vapor deposition (PVD).

The dielectric material 42 may comprise any suitable composition orcombination of compositions; and in some embodiments may comprise anon-oxygen-containing material; such as, for example, silicon nitride.

The dielectric material 44 may comprise any suitable composition orcombination of compositions; and in some embodiments may comprise one ormore of silicon dioxide, silicon nitride, etc.

Referring to FIGS. 16-18, chemical-mechanical polishing (CMP) or othersuitable planarization is utilized to remove materials 42 and 44 fromover material 38 of patterning structures 34-36, and form the shownplanarized surface 45.

In some embodiments, the construction of FIGS. 16-18 may be consideredto comprise an arrangement of heater element material strips 46-51 whichextend along a direction of axis 5. Each heater element strip extendsacross a plurality of underlying nodes 32, as shown in FIG. 18 where thestrip 48 extends across several nodes 32.

The strips 46-51 are spaced from one another by intervening materialcorresponding to the dielectric materials 38, 42 and 44. The planarizedsurface 45 extends across the strips 46-51, and across the interveningmaterial between such strips.

In the shown embodiment, each of the strips comprises a horizontalportion 56 (one of which is labeled in FIG. 17) and a non-horizontalportion 58 (one of which is labeled in FIG. 17). The horizontal portionis over and directly against an underlying node 32, and thenon-horizontal portion extends upwardly from the horizontal portion at acorner 59 (one of which is labeled in FIG. 17). In the shown embodiment,the non-horizontal portions are substantially orthogonal to thehorizontal portions, and accordingly the corners 59 are about 90°. Inother embodiments, the corners 59 may have other angles.

In some embodiments, corners 59 may be referred to as inside corners,and each of the heater material strips 46-51 may be considered tocomprise an interior sidewall 60 (one of which is labeled in FIG. 17)along the inside corner, and to comprise an exterior sidewall 61 (one ofwhich is labeled in FIG. 17) in opposing relation to the interiorsidewall.

Referring to FIGS. 19-21, phase change material 62 is formed across theplanarized surface 45. The phase change material may be of any suitablecomposition or combination of compositions. In some embodiments, thephase change material may comprise, consist essentially of, or consistof a chalcogenide; such as, for example, a mixture of germanium,antimony and tellurium (i.e., a mixture commonly referred to as GST).The phase change material is an example of an oxygen-sensitive material;with the term “oxygen-sensitive material” meaning a material which isaltered in a non-desired manner upon exposure to oxygen. In someembodiments, processing described herein protects regions of theoxygen-sensitive material from exposure to oxygen. Such may alleviate orprevent oxygen-induced degradation of such regions of theoxygen-sensitive material. Although the example oxygen-sensitivematerial described herein is phase change material, in other embodimentsanalogous processing to that described herein may be utilized for otheroxygen-sensitive materials.

The phase change material may be ultimately incorporated into memorycells as a programmable material, and thus may be referred to asprogrammable material in some embodiments. The regions of theprogrammable material that are protected from oxygen-induced degradationmay be the regions that are within the memory cells. For instance, inthe shown embodiment, some of the oxygen-sensitive material 62 isdirectly against dielectric material 42 and some is directly againstdielectric material 44. In some embodiments, all regions of thedielectric material that are directly against the oxygen-sensitivematerial 62 will not comprise oxygen; and accordingly will benon-oxygen-containing material, such as silicon nitride. In someembodiments, it is recognized that material 42 is directly againstregions of material 62 that are within memory cells and so material 42is a non-oxygen-containing material; and it is recognized that material44 is directly against regions of material 62 that are not within memorycells, and so it less important whether or not material 44 comprisesoxygen. Thus material 44 may be a non-oxygen-containing material (e.g.,silicon nitride), or may be an oxygen-containing material (e.g., silicondioxide).

Electrode material 64 is formed over phase change material 62, and inthe shown embodiment directly contacts the phase change material at aninterface 63 (in other embodiments, there may be one or more additionalmaterials between the phase change material and the electrode material).The electrode material may comprise, consist essentially of, or consistof carbon. Such carbon may be in any suitable form (e.g., graphene,etc.). The carbon-containing material 64 preferably contains little orno oxygen so that there will not be oxygen from the material 64poisoning oxygen-sensitive material 62 within the memory cells.Carbon-containing material 64 may be formed to any suitable thickness;and in some embodiments may be formed to a thickness of from about 40nanometers to about 200 nanometers. The carbon-containing material maybe homogeneous (as shown), or may comprise two or more discretecompositions in a heterogeneous arrangement. In some embodiments, thecarbon-containing material may comprise two or more layers of differentcomposition relative to one another.

Referring to FIGS. 22-24, material 64 is patterned into a plurality oflines 70-73. The pattern of the lines is also transferred into materials38, 40, 42, 44 and 62. Such etches the strips 46-51 (FIGS. 16-18) ofheater material 40 into heater elements 74 that are in one-to-onecorrespondence with nodes 32 (for example, etches the line 48 of FIG. 21into a plurality of heater elements 74 shown in FIG. 24).

In the shown embodiment, the lines 70-73 extend along the direction ofaxis 7, and thus are substantially orthogonal to the strips 46-51 (FIGS.16-18). In other embodiments, the lines 70-73 may be formed along adirection which intersects the strips 46-51 (FIGS. 16-18), but which isnot orthogonal to the strips.

FIG. 24 shows that the lines 70-73 have sidewalls 75 (only some of whichare labeled) which extend upwardly from lateral edges 77 (only some ofwhich are labeled) of the heater elements 74. The heater elements 74 areconfigured as angled plates comprising horizontal portions 56 (one ofwhich is labeled in FIG. 23) joining to non-horizontal portions 58 (oneof which is labeled in FIG. 23) through corners 59 (one of which islabeled in FIG. 23). Each heater element 74 comprises an interiorsidewall 60 and an exterior sidewall 61 (the terms “exterior sidewall”and “interior sidewall” were described above with reference to FIGS.16-18). The interior and exterior sidewalls extend to the lateral edges77 of FIG. 24; and in some embodiments such lateral edges may beconsidered to bridge the interior sidewalls to the exterior sidewalls.

The phase change programmable material 62 and carbon-containingelectrode material 64 are comprised by electrode/programmable lines70-73 at the processing stage of FIGS. 22-24. Such lines extend acrossthe heater elements 74. Accordingly, each of the heater structures 74may be incorporated into a separate memory cell, with individual memorycells comprising a heater element in combination with the programmablematerial 62 and electrode material 64 directly above the element in theshown embodiment. In some embodiments, memory cell structures containingregions of the electrode/programmable material lines 70-73 together withthe heater elements 74 may be considered to have sidewalls 75/77 thatextend along the heater element material 40, the phase change material62 and the carbon-containing material 64.

Referring to FIGS. 25-27, protective material 80 is formed over andbetween lines 70-73. Material 80 may comprise any suitablenon-oxygen-containing composition or combination of compositions. Insome embodiments, material 80 may comprise, consist essentially of, orconsist of silicon nitride. Material 80 may be formed with any suitableprocessing, including, for example, one or more of ALD, CVD and PVD. Insome embodiments, the material 80 may have a thickness within a range offrom about 5 nanometers to about 10 nanometers.

Referring to FIGS. 28-30, material 80 is anisotropically etched topattern the material into spacers 82 (only some of which are labeled)that extend along the sidewalls 75/77. The anisotropic etching removesmaterial 80 from along top regions 84 (only some of which are labeled inFIG. 30) of lines 70-73, while leaving the protective material acrossinterfaces 63 where phase change material 62 contacts carbon-containingmaterial 64.

Referring to FIGS. 31-33, dielectric material 85 is formed between lines70-73 and over material 80. The dielectric material 85 may comprise anysuitable composition or combination of compositions, and in someembodiments may be an oxygen-containing material. For instance, in someembodiments material 85 may comprise one or more of silicon dioxide,BPSG, PSG, aluminum oxide, etc.

The dielectric material 85 may be initially formed to fill gaps betweenlines 70-73 and to extend across the lines 70-73. Subsequently, CMP orother appropriate processing may be utilized to remove the dielectricmaterial from over lines 70-73 and form the shown planarized surface 83extending across materials 85 and 64.

Referring to FIGS. 34-36, protective material 86 is formed overplanarized surface 83, and dielectric material 88 is formed over theprotective material.

Protective material 86 may be a non-oxygen-containing material; and may,for example, comprise, consist essentially of, or consist of siliconnitride. The protective material 86 may be referred to as a secondprotective material to distinguish it from the first protective material80. In some embodiments, the protective materials 80 and 86 may comprisea same composition as one another, and in other embodiments they maycomprise different compositions relative to one another.

The protective material 86 may be formed to any suitable thickness, andin some embodiments may be formed to a thickness within a range of fromabout 20 nanometers to about 40 nanometers.

The dielectric material 88 may comprise any suitable composition orcombination of compositions, and in some embodiments may compriseoxygen-containing material. For instance, in some embodiments dielectricmaterial 88 may comprise silicon dioxide, BPSG, PSG, aluminum oxide,etc.

Referring to FIGS. 37-39, trenches 90-93 are etched through materials 86and 88 to expose carbon-containing material 64 of lines 70-73. In theshown embodiment, trenches 90, 92 and 93 are aligned with lines 70, 71and 73, respectively; and trench 91 is misaligned relative to theunderlying line 71. The misaligned trench 91 exposes the dielectricmaterial 85 adjacent line 71. However, the problem described above withreference to FIG. 3 is avoided due to dielectric material 85 having adifferent composition than protective material 86. Specifically, theetching utilized to penetrate material 86 and form misaligned trench 91stops at dielectric material 85, rather than penetrating along the sideof line 71.

Referring to FIGS. 40-42, electrically conductive material 94 is formedwithin the trenches 90-93. Such electrically conductive material maycomprise any suitable composition or combination of compositions; and insome embodiments may comprise one more of various metals,metal-containing compositions and conductively-doped semiconductormaterials. For instance, in some embodiments conductive material 94 maycomprise copper surrounded by copper barrier material (for instance,ruthenium-containing material, tantalum-containing material, etc.).

The conductive material 94 is electrically coupled withcarbon-containing material 64, and in the shown embodiment directlycontacts the carbon-containing material 64.

The conductive material 94 is patterned into conductive structures(specifically, lines) 100-103 within trenches 90-93, respectively. Suchpatterning may be accomplished with a damascene-type process where theconductive material is provided to initially overfill trenches 90-93 andthen excess conductive material is removed with CMP or other suitableplanarization to form the structure of FIGS. 40-42.

In the shown embodiment, the structures 100, 102 and 103 are entirelyover the carbon-containing material 64 due to trenches 90, 92 and 93having been properly aligned with such carbon-containing material at theprocessing stage of FIGS. 37-39. In contrast, the structure 101 is onlypartially over the underlying carbon-containing material 64, and alsoextends partially over dielectric material 85. Such is due to themisalignment of trench 91 at the processing stage of FIGS. 37-39.Accordingly, in the shown embodiment the bottom surfaces of conductivestructures 100, 102 and 103 only directly contact carbon-containingmaterial 64, while the bottom surface of conductive structure 101directly contacts both the underlying carbon-containing material 64 andthe dielectric material 85.

FIG. 42 illustrates an embodiment in which conductive material 94 ofmisaligned structure 101 is entirely over the carbon-containing material64. Such structure may result if the etch described above with referenceto FIG. 39 forms a misaligned trench 91 which does not penetrate intodielectric material 85. In other embodiments, the misaligned trench maypenetrate into dielectric material 85, and accordingly a structure maybe formed in which conductive material 94 extends downwardly alongsidewalls of carbon-containing material 64 and oxygen-sensitive material62. FIG. 43 shows a construction 10a having a structure 101a analogousto that of the structure 101 of FIG. 42, but in which conductivematerial 94 extends downwardly along sidewalls of carbon-containingmaterial 64 and oxygen-sensitive material 62. The protective material 80advantageously protects a sidewall of oxygen-sensitive material 62 frombeing directly exposed by the misaligned trench (analogous to the trench91 of FIG. 39, but extending into dielectric material 85), and laterallyspaces material 94 from the oxygen-sensitive material 62.

In the embodiments described above with reference to FIGS. 4-42, PCMcells are formed to comprise phase change material 62 over heatingelements 74 (described above with reference to FIGS. 22-24). In otherembodiments analogous to those described herein, phase change materialmay be utilized without heating elements (i.e., utilized in self-heatingmemory cells), and the phase change material may be patterned intostructures analogous to the angled plate structures of heating elements74. Also, although the example embodiments described above form PCMcells, in other embodiments analogous processing may be utilized to formother constructions comprising oxygen-sensitive material.

The structures described herein may be incorporated into any of numerousintegrated circuit configurations, and such configurations may beutilized in electronic systems. The electronic systems may be used inany of numerous applications such as, for example, memory modules,device drivers, power modules, communication modems, processor modules,and application-specific modules, and may include multilayer, multichipmodules. The electronic systems may be any of a broad range of systems,such as, for example, clocks, televisions, cell phones, personalcomputers, automobiles, industrial control systems, aircraft, etc.

The particular orientation of the various embodiments in the drawings isfor illustrative purposes only, and the embodiments may be rotatedrelative to the shown orientations in some applications. The descriptionprovided herein, and the claims that follow, pertain to any structuresthat have the described relationships between various features,regardless of whether the structures are in the particular orientationof the drawings, or are rotated relative to such orientation.

The cross-sectional views of the accompanying illustrations only showfeatures within the planes of the cross-sections, and do not showmaterials behind the planes of the cross-sections in order to simplifythe drawings.

When a structure is referred to above as being “on” or “against” anotherstructure, it can be directly on the other structure or interveningstructures may also be present. In contrast, when a structure isreferred to as being “directly on” or “directly against” anotherstructure, there are no intervening structures present. When a structureis referred to as being “connected” or “coupled” to another structure,it can be directly connected or coupled to the other structure, orintervening structures may be present. In contrast, when a structure isreferred to as being “directly connected” or “directly coupled” toanother structure, there are no intervening structures present.

Some embodiments include a method of forming a semiconductorconstruction. Carbon-containing material is formed over oxygen-sensitivematerial. The carbon-containing material and oxygen-sensitive materialtogether form a structure having a sidewall that extends along both thecarbon-containing material and the oxygen-sensitive material. Firstprotective material is formed along the sidewall. The first protectivematerial extends across an interface of the carbon-containing materialand the oxygen-sensitive material, and does not extend to a top regionof the carbon-containing material. Second protective material is formedacross the top of the carbon-containing material. The first and secondprotective materials comprise a common composition as one another. Thesecond protective material is etched to expose an upper surface of thecarbon-containing material.

Some embodiments include a method of forming a memory array. A pluralityof spaced-apart electrical nodes is formed to be supported by asemiconductor substrate. An arrangement of heater element materialstrips and intervening material is formed over the nodes. The stripsextend along a first direction and across pluralities of the nodes. Eachstrip has a horizontal portion directly against the nodes and has anon-horizontal portion extending upwardly from the horizontal portion.The intervening material is between the strips. A first planarizedsurface extends across the strips and the intervening material. Phasechange material is formed across the first planarized surface.Carbon-containing material is formed over the phase change material. Thecarbon-containing material, phase change material and heater elementmaterial strips are patterned to form structures having sidewalls thatextend along the heater element material, the carbon-containing materialand the phase change material. The carbon-containing material and phasechange material of such structures are configured as lines extendingalong a second direction that intersects the first direction. Firstprotective material is formed over and between the structures. The firstprotective material is anisotropically etched to pattern the firstprotective material into protective spacers along the sidewalls of thestructures. The spacers extend across interfaces of thecarbon-containing material and the phase change material, and do notextend to a top region of the carbon-containing material. Dielectricmaterial is formed between the structures and over the spacers. Thedielectric material is planarized to remove the dielectric material fromover the structures and to form a second planarized surface extendingacross the dielectric material and the structures. Second protectivematerial is formed across the second planarized surface. The secondprotective material is etched to form trenches extending along the lineswhich expose carbon-containing material of the lines. Electricallyconductive material is formed within the trenches and electricallycoupled with the carbon-containing material.

Some embodiments include a semiconductor construction having anoxygen-sensitive material over a supporting substrate. Acarbon-containing material is over the oxygen-sensitive material. Thecarbon-containing material and oxygen-sensitive material are togetherconfigured as a structure having a sidewall that extends along both thecarbon-containing material and the oxygen-sensitive material. A firstprotective material is along the sidewall. The first protective materialextends across an interface of the carbon-containing material and theoxygen-sensitive material, and does not extend to a top region of thecarbon-containing material. Dielectric material is spaced from theoxygen-sensitive material by the first protective material. Thedielectric material has an upper surface adjacent an upper surface ofthe carbon-containing material. A second protective material is over thedielectric material. The first and second protective materialscomprising a common composition as one another. A conductive structureextends through the second protective material and directly contacts thecarbon-containing material.

Some embodiments include a memory array having spaced-apart electricalnodes supported by a semiconductor substrate. Heater elements aredirectly over the nodes. The heater elements are angled plates havinghorizontal portions directly against the nodes and having non-horizontalportions extending upwardly from the horizontal portions. Each angledplate has an interior sidewall where an inside corner is formed betweenthe non-horizontal portion and the horizontal portion, an exteriorsidewall in opposing relation to the interior sidewall, and lateraledges between the interior and exterior sidewalls.Electrode/programmable material lines are over the heater elements. Theelectrode/programmable material lines comprise phase change materialover the heater elements and comprise carbon-containing material overand directly against the phase change material. Theelectrode/programmable material lines have sidewalls that extend alongboth the carbon-containing material and the phase change material. Thesidewalls extend upwardly from the lateral edges of the heater elements.The lines extend along a first direction. Silicon nitride-containingspacers are along the sidewalls. The spacers extend across interfaces ofthe carbon-containing material and the phase change material, and do notextend to a top region of the carbon-containing material.Oxygen-containing dielectric material is between the lines and over thespacers. Silicon nitride-containing material is over theoxygen-containing dielectric material. Electrically conductivestructures extend through the silicon nitride-containing material anddirectly contact the carbon-containing material of the lines. Theelectrically conductive structures are lines at least partially directlyover the electrode/programmable material lines and extend along thefirst direction.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

1. A method of forming a semiconductor construction, comprising: formingcarbon-containing material over oxygen-sensitive material; thecarbon-containing material and oxygen-sensitive material togetherforming a structure having a sidewall that extends along both thecarbon-containing material and the oxygen-sensitive material; formingfirst protective material along the sidewall, the first protectivematerial extending across an interface of the carbon-containing materialand the oxygen-sensitive material, and not extending to a top region ofthe carbon-containing material; forming second protective materialacross the top of the carbon-containing material, the first and secondprotective materials comprising a common composition; and etchingthrough the second protective material to expose an upper surface of thecarbon-containing material.
 2. The method of claim 1 wherein the firstand second protective materials comprise silicon nitride.
 3. The methodof claim 1 wherein the first and second protective materials consistessentially of silicon nitride.
 4. The method of claim 1 wherein thefirst and second protective materials consist of silicon nitride.
 5. Themethod of claim 1 wherein the carbon-containing material consistsessentially of carbon.
 6. The method of claim 1 wherein thecarbon-containing material consists of carbon.
 7. The method of claim 1wherein the oxygen-sensitive material is a phase change material.
 8. Themethod of claim 1 wherein the oxygen-sensitive material compriseschalcogenide.
 9. The method of claim 1 wherein the oxygen-sensitivematerial comprises GST.
 10. The method of claim 1 further comprisingforming an electrically conductive material at the exposed upper surfaceof the carbon-containing material.
 11. A method of forming a memoryarray, comprising: forming a plurality of spaced-apart electrical nodessupported by a semiconductor substrate; forming an arrangement of heaterelement material strips and intervening material over the nodes, thestrips extending along a first direction and across pluralities of thenodes; each strip having a horizontal portion directly against the nodesand having a non-horizontal portion extending upwardly from thehorizontal portion; the intervening material being between the strips; afirst planarized surface extending across the strips and the interveningmaterial; forming phase change material across the first planarizedsurface; forming carbon-containing material over the phase changematerial; patterning the carbon-containing material, phase changematerial and heater element material strips to form structures havingsidewalls that extend along the heater element material, thecarbon-containing material and the phase change material; thecarbon-containing material and phase change material of such structuresbeing configured as lines extending along a second direction thatintersects the first direction; forming first protective material overand between the structures; anisotropically etching the first protectivematerial to pattern the first protective material into protectivespacers along the sidewalls of the structures; the spacers extendingacross interfaces of the carbon-containing material and the phase changematerial, and not extending to a top region of the carbon-containingmaterial; forming dielectric material between the structures and overthe spacers; planarizing the dielectric material to remove thedielectric material from over the structures and form a secondplanarized surface extending across the dielectric material and thestructures; forming second protective material across the secondplanarized surface; etching through the second protective material toform trenches extending along the lines and exposing carbon-containingmaterial of the lines; and forming electrically conductive materialwithin the trenches and electrically coupled with the carbon-containingmaterial.
 12. The method of claim 11 wherein the phase change materialcomprises chalcogenide.
 13. The method of claim 11 wherein the phasechange material comprises GST.
 14. The method of claim 11 wherein thedielectric material comprises oxygen.
 15. The method of claim 11 whereinthe electrically conductive material comprises copper.
 16. The method ofclaim 11 wherein the first and second protective materials comprise acommon composition.
 17. The method of claim 11 wherein the first andsecond protective materials consist of silicon nitride.
 18. The methodof claim 11 wherein the dielectric material is a first dielectricmaterial, and further comprising forming a second dielectric materialover the second protective material; the trenches being formed throughboth the second dielectric material and the second protective material;the first and second dielectric materials both comprising oxygen. 19-36.(canceled)
 37. The method of claim 11 wherein the dielectric material isa first dielectric material, and further comprising forming a seconddielectric material over the second protective material; the trenchesbeing formed through both the second dielectric material and the secondprotective material; the first and second dielectric materials bothcomprising silicon and oxygen.